Your heap is actually using 6.5 GB of virtual memory (this may include the perm gen)
You have a bunch of threads using 64 MB stacks. Not clear why some are and others are using the default 1 MB.
The total is 9.3 million KB of virtual memory. I would only worry about the resident size.
Try using top to find the resident size of the process.
You may find this program useful
BufferedReader br = new BufferedReader(new FileReader("C:/dev/gistfile1.txt"));
long total = 0;
for(String line; (line = br.readLine())!= null;) {
String[] parts = line.split("[- ]");
long start = new BigInteger(parts[0], 16).longValue();
long end = new BigInteger(parts[1], 16).longValue();
long size = end - start + 1;
if (size > 1000000)
System.out.printf("%,d : %s%n", size, line);
total += size;
}
System.out.println("total: " + total/1024);
Unless you have a JNI library using the memory, my guess is you have lots of threads which each have their own stack space. I would check the number of threads you have. You can reduce the maximum stack space per thread, but a better option might be to reduce the number of threads you have.
The off heap memory is by definition unmanaged, so it is not easily “tuned” as such. Even tuning the heap is not simple.
The default stack size on 64-bit JVMs is 1024K so 700 threads will be using 700 MB of virtual memory.
You shouldn’t confuse virtual memory sizes for resident memory sizes. Virtual memory on a 64-bit application is almost free and it’s only the resident size you should worry about.
The way I see it you have 9.3 GB total.
- 6.0 GB heap.
- 128 MB perm gen
- 700 MB stacks.
- < 250 shared libraries
- 2.2 GB of unknown (I suspect virtual memory not resident memory)
The last time some one had this problem they had a lot more threads than they though they should. I would check the maximum number of threads you had as it is the peak which determines the virtual size. e.g. was it closer to 3000?
Hmmm each of these pairs is a thread.
7f0cffddf000-7f0cffedd000 rw-p 00000000 00:00 0
7f0cffedd000-7f0cffee0000 ---p 00000000 00:00 0
and these suggest you have slightly less than 700 threads now…..